…my sources tell me that the first mega-patch for Windows Phone has sat undeployed on Microsoft’s servers because the software giant’s wireless carrier partners–contrary to another unfulfilled promise–have refused to OK it for release.

There have been many complaints about the vague and sliding release dates of the much-anticipated WP7 update; if what Thurrott says is true, it may serve to silence detractors complaining about Microsoft’s poor handling of the release schedule (Paul Thurrott himself among them), but also gives an alarming impression of the balance of power between Microsoft and the carriers.

Half the point of WP7 was to give Microsoft greater control over the user experience and ensure consistency through homogeneous software. It’s succeeded so far in keeping the handsets free of the carrier-installed crapware that infects Android and previous versions. But if Thurrott’s sources are right, carriers are once more damaging the user experience; we can only wonder what it is in the update that they object to so much.